Semi-polar hyperdispersants for pigment bases

ABSTRACT

Quaternized oligourethanes, useful as dispersing agents in preparing high-solids pigment concentrates for use in manufacturing inks, especially inks intended for use in gravure and packaging applications. The novel oligourethanes are prepared by reacting an appropriate ester or alcohol with a hydroxyethylimidazoline and polyisocyanate followed by quaternization with acids or alkyl derivatives of acids.

This application is a continuation-in-part of co-pending applicationSer. No. 190,623, filed May 5, 1988 and now abandoned.

This invention relates to quaternized oligourethanes which are useful asdispersing agents in preparing high-solids pigment concentrates for usein the manufacture of inks, especially inks intended for use in gravureand packaging applications.

BACKGROUND OF THE INVENTION

Due to the economics of the ink business today, it is highly desirableto be able to process pigments into high-solids concentrates. Typically,such concentrates would contain from 30 to 60% pigment. Ideally, theycould be let down in a wide variety of vehicles in order to produce awide range of finished inks.

The economic advantages offered by such concentrates are twofold. First,they would greatly reduce the inventory of intermediates which must becarried by an ink plant. Only one intermediate dispersion would beneeded for each pigment versus the several which are now typically used.Second, energy consumption would be considerably reduced. The higher thepigment concentration at which dispersion can be effected, the less thetotal volume of material that must be processed through a mill andtherefore the less total energy consumed in processing the pigment.

Traditionally, vehicles for lithographic inks are composed of alkydresins and/or rosin derivatives and/or hydrocarbon resins, together withhigh-boiling hydrocarbon solvents. It is known in the art thatsatisfactory dispersions containing 30 to 60% pigment cannot be preparedusing such traditional vehicle components alone. Usually mixtures atsuch solids levels cannot be processed in standard milling equipment. Inthe few cases where they can be processed, they yield dispersions withunacceptable rheological properties, i.e. dispersions which cannot bepumped or otherwise conveniently transferred from one vessel to another.Such dispersions usually also show inferior color development and pooraging stability.

Recently attempts have been made to overcome the above-describedproblems by using compounds which are better dispersants for pigmentsthan are the traditional alkyd resins and rosin derivatives. Forexample, U.S. Pat. No. 4,224,212 describes the use of dispersing agentsattained by reacting a poly (lower alkylene) imine with a polyesterhaving free carboxylic acid groups to form reaction products containingat least two polyester chains attached to each poly (lower alkylene)imine chain. Preferred polyesters are the polyesters of an hydroxycarboxylic acid of the formula HO-R-COOH where R is a divalent aliphaticradical containing at least 8 carbon atoms in which there are at least 4carbon atoms between the hydroxy and carboxylic acid groups. Preferredpolyesters are also the polyesters formed from a mixture ofaforementioned hydroxy carboxylic acids with a carboxylic acid which isfree from hydroxy groups.

U.S. Pat. No. 4,415,705 describes the use of rosin derivatives asdispersants. These dispersants are attained by reacting a poly (loweralkylene) imine having a molecular weight of 1,000 to 15,000 with apolyester obtained by esterifying hydroxy stearic acid or its oligomer,with tall oil rosin. This patent states that such dispersants have beenfound to be superior to products made from wood rosin or gum rosin.

SUMMARY OF THE INVENTION

A novel class of quaternized oligourethanes has been discovered. Thesequaternized oligourethanes have been found to be very useful inpreparing non-flocculating dispersions of high loadings of inorganic ororganic pigments or dyestuffs. Such dispersions have been found toproduce inks which yield excellent results especially when such inks areutilized for gravure and packaging applications.

DETAILS OF THE PRESENT INVENTION

The novel quaternized oligourethanes of the present invention may berepresented by the formula: ##STR1## wherein X represents the radical##STR2## such that when X is ##STR3## R' is an ester resulting from thereaction of a C₂ -C₁₈ hydroxyalkanoic acid or a C₃ -C₁₈ hydroxyalkenoicacid and rosin, and when X is ##STR4## R' is a C₃ -C₁₈ linear orbranched alkyl, phenyl, alkaryl, aralkyl, cycloalkyl or the radical##STR5## wherein Y is hydrogen or methyl, R'" is a C₁ -C₆ alkyl and m isan integer of 1 to 20;

R is a C₁₁ -C₁₇ linear or branched alkyl, alkenyl, alkynyl orcycloalkyl;

R" is a C₆ -C₁₄ linear or branched alkyl, phenyl, alkaryl, aralkyl orcycloalkyl or a dimer or trimer thereof;

R"" is hydrogen or a C₁ -C₄ linear or branched alkyl; and

Z is R""OSO₃, Cl, Br, I, NO₃ R'""SO₃, (R"")_(3-n) H_(n) PO₄ or(R"")_(3-n) H_(n) PO₃ wherein n is an integer of 0 to 3, and R'"" isphenyl, CF₃, C₁ -C₄ linear or branched alkyl or C₇ -C₁₂ aralkyl oralkaryl.

The rosin which is used for reaction with hydroxyalkanoic acid orhydroxyalkenoic acid may be wood rosin, gum rosin or tall oil rosin, buttall oil rosin is preferred.

Preferably, in the general formula given above, X is a urethane radicali.e. ##STR6## Preferably the ester is that which results from thereaction of a C₆ -C₁₈ hydroxy alkanoic acid with tall oil rosin.

In the above general formula, it is preferred that R' be the radical##STR7## wherein Y is hydrogen or methyl, R'" is a C₁ -C₆ alkyl,preferably a C₂ -C₄ alkyl and m is an integer of 1 to 20, preferably 2to 10. It is also preferred that R" be a C₇ -C₁₃ aralkyl or alkaryl andZ be R""OSO₃.

The quaternized oligourethanes are excellent dispersing agents fordispersing solid materials in organic liquids. The dispersion can beobtained by any of the conventional and well known methods of preparingdispersions. Thus the solid, the organic liquid and the dispersing agentmay be mixed in any order and the mixture then subjected to a mechanicaltreatment to reduce the particle size of the solid, for example by ballmilling, bead milling, gravel milling or plastic milling until thedispersion is formed.

Alternatively, the solid can be treated to reduce its particle sizeindependently or in admixture with either the organic liquid or thedispersing agent, and the other ingredient or ingredients then addedfollowing which dispersion can be obtained by stirring the mixture. Adispersion obtained in this way and comprising the solid in finelydivided form and one or more dispersing agents is a further feature ofthis invention.

The amount of dispersing agent present in the dispersion is generally inthe range of 1-20 wt. %, based on the weight of the dispersion. Thedispersion generally contains 30-75 wt. % of the solid material and10-50 wt. % of the organic liquid, based on the weight of thedispersion. It may also be helpful to incorporate up to 5 wt. %, basedon the weight of the dispersion, of a nonionic surfactant such assorbitol monooleate, glycerol monooleate, polyethylene glycol mono nonylphenyl ether, poly(ethylene-co-propylene)glycol mono octyl phenyl ether,ethoxylated sorbitan esters, long chain fatty acid esters ofpolyethyleneglycol, lecithin, tertiary acetylenic diols, etc. The solidmay be any particulate solid material of an inorganic or organic naturewhich is substantially insoluble in the organic liquid at the desiredtemperature of usage and which is capable of comminution into a finelydivided form. This invention is of particular value when the solid is apigment or dyestuff. For the purposes of this invention, the term"pigment" includes both inorganic and organic pigments and also lakesand toners.

As examples of organic pigments there may be mentioned azo, thionindigo,anthraquinone, anthanthrone and isodibenzanthrone pigments, vat dyepigments, triphenodioxazine pigments, phthalocyanine pigments forexample copper phthalocyanine, its nuclear chlorinated derivatives andcooper tetraphenyl or octaphenyl phthalocyanine and other heterocyclicpigments, for example linear quinacridone.

As examples of inorganic pigments there may be mentioned chrome pigmentsincluding the chromates of lead, zinc, barium and calcium and variousmixtures and modifications such as are commercially available aspigments of greenish-yellow to red shades under the names primrose,lemon, middle orange, scarlet and red chromes. Modified chrome pigmentsmay contain for example sulphate radicals and/or additional metals suchas aluminium, molybdenum and tin. Further examples of inorganic pigmentsare carbon black, titanium dioxide, zinc oxide, Prussian Blue and itsmixtures with chrome yellows which are known as Brunswick Greens orchrome greens, cadmium sulphide and sulphoselenide, iron oxides,vermilion and ultramarine. These and various other pigments suitable foruse in the present invention are described in Volume 2 of "Colour Index6 2nd Edition," published jointly in 1956 by the Society of Dyers andColourists and the American Association of Textile Chemists andColourists, under the heading of "Pigments" and in subsequent authorizedamendments thereto.

The term "lake" denotes a water-insoluble metal salt or complex of anorganic dyestuff which has been precipitated on a water-insolubleinorganic substrate such as alumina.

The term "toner" denotes a water-insoluble metal salt or complex, inparticular a calcium or barium salt or complex, of a soluble orsparingly soluble organic dyestuff, in particular an azo dyestuff, whichhas optionally been prepared in the presence of an extender such asrosin.

As specific examples of the said lakes and toners there may be mentionedthe barium toner of1-(2'-sulpho-4'-methyl-5'-chlorophenylazo)-2-hydroxy-3-naphthoic acid,the nickel complex of 3-(4'-chlorophenylazo)-quinoline-2,4-diol, therosinated barium toner of1-(2'-sulpho-4'-chloro-5'-methylphenylazo)-2-naphthol, the aluminiumlake of 1,4-dihydroxyanthraquinone-2-sulphonic acid and, above all, arosinated calcium toner of1-(2'-sulpho-4'-methylphenylazo)-2-hydroxy-3-naphthoic acid.

Especially preferred pigments for use in the present invention are thosetypically employed for gravure and packaging ink systems such asdiarylide yellow, BON Red, carbon black, Red Lake C, Lithol Rubine,phthalocyanine blue, phthalocyanine green, molybdenum orange andtitanium dioxide.

Dyestuffs which are useful in the present invention are those which arewater soluble or water-insoluble such as basic, acid and directdyestuffs. The dyestuffs include azo types such as monoazo and diazo andmetal derivatives thereof, anthraquinone, nitro, phthalocyanine,methine, styryl, naphthoperinone, quinaphthalone, diarylmethane,triarylmethane, xanthine, azine, oxazine and thiazine dyestuffs. Ifdesired the dyestuffs can be reactive dyestuffs which contain groupscapable of forming covalent bonds with textile materials.

Any organic liquid may be used in the dispersion but hydrocarbons arepreferred. As examples of such liquids there are mentioned aromatichydrocarbons such as benzene, toluene, xylene, aliphatic andcycloaliphatic hydrocarbons such as petroleum fractions, white spiritand cyclohexane, and high boiling mineral oils such as spindle oil.Alternative organic liquids are halogen substituted hydrocarbons such aschlorobenzene, trichloroethylene, perchloroethylene,1,1,1-trichloroethane, methylene dichloride, chloroform,1,1,2-trichloro-1,2,2-trifluoroethane, carbon tetrachloride,tetrachloroethane or dibromoethylene and mixtures of these compounds,esters such as ethyl acetate, propyl acetate and butyl acetate and heatbodied linseed oils used as lithographic varnish media and ketones suchas methylethylketone methylisobutyl ketone and cyclohexanone. Mixturesof such solvents may be used. The solvents may contain other materialsin solution, for example the alkyd, nitrocellulose, acrylic,urea/formaldehyde, melamine/formaldehyde or other resins used in paintmedia or zinc/calcium rosinates used in gravure ink media. Especiallypreferred solvents are aliphatic hydrocarbons which are compatible withgravure and packaging ink systems, such as hexanes, heptanes, octanes,cyclohexane, methylcyclohexane, lactol spirits, naphtha and mineralspirits.

The dispersions of this invention are fluid or semi-fluid compositionscontaining the solid in finely divided and usually deflocculated form,and can be used for any purpose for which dispersions of theseparticular solids are conventionally used. Thus the pigment dispersionsare of value in the manufacture of printing inks particularlypublication gravure and packaging inks by incorporating the dispersionswith the other components conventionally used in the manufacture of suchinks. Typically such inks will contain a pigment dispersed in an inkvehicle such as a liquid petroleum hydrocarbon solution of the ink, plusresin and 1-20 wt% of the quaternized oligourethane of this invention.These dispersions are also of value in the manufacture of paints, forwhich purpose the dispersions are incorporated into conventional alkydor other resins.

The dyestuff dispersions are useful in the preparation of textileprinting inks or solvent dyeing systems and particularly where thedyestuff is a sublimable disperse dyestuff useful in transfer printing.Inks and paints containing such dispersants are further features of thepresent invention.

The process for preparing the novel quaternized oligourethanes of thisinvention will depend on whether it is desired to make a product whereinX in the general formula above is to be the amide radical ##STR8## orthe urethane radical ##STR9## If a product is desired with the amideradical, then the 3-step process outlined below is followed. If aproduct containing the urethane radical is desired then the 2-stepprocess outlined below is followed.

The 3-step process involves:

(a) reacting a C₂ -C₁₈ hydroxyalkanoic acid or a C₃ -C₁₈ hydroxyalkenoicacid with rosin in the presence of an esterification catalyst;

(b) reacting the ester resulting from step (a) with a C₁₁ -C₂₁hydroxyethylimidazoline and a C₆ -C₁₄ polyisocyanate;

(c) quaternizing the oligourethane resulting from step (b) by reactingit with a C₁ -C₄ linear or branched alkyl halide, alkyl nitrate, alkylphosphate, alkyl phosphite, alkyl sulfate, aryl sulfonate, alkylsulfonate or a mineral acid or halogen acid.

The acid may be a C₃ -C₁₈ hydroxyalkenoic acid such as 4-hydroxybutenoicacid, 4-hydroxy-3-pentenoic acid, castor fatty acid 6-hydroxy-3-hexenoicacid and the like, but is preferably a C₆ -C₁₈ hydroxyalkanoic acid suchas commercial 12-hydroxystearic acid, w-hydroxycaproic acid, glycolicacid, 4-hydroxybutyric acid, 10-hydroxydecanoic acid,2-hydroxyisocaproic acid and the like are also useful. As for the rosin,it is preferably tall oil rosin, although wood rosin or gum rosin arealso useful.

The esterification reaction is carried out in the presence of anesterification catalyst generally at elevated temperatures in the rangeof about 170° to 210° C. for about 8 to 18 hours. Useful esterificationncatalysts include dibutyltin oxide, tetrabutyl titanate,triphenylphosphite, p-toluenesulfonic acid, sulfuric acid, etc.Typically, the ratio of acid to rosin will be in the range of 1 to 6moles of acid per mole of rosin. It is preferred that the relativeproportions of acid and rosin be selected such that each oligomermolecule will contain up to one carboxyl group and the degree ofesterification is between n=1 to n=6. The resultant carboxyl-terminatedpolyester will have a typical acid value of 70+5 mg KOH/g sample.

In step (b), 0.2-0.8 mole of ester from step (a) is reacted with 0.8-0.2mole of the hydroxyethylimidazoline as well as with 0.8-1.0 mole ofpolyisocyanate. Desirably, this reaction is carried out in the presenceof a catalyst such as stannous octoate. Preferredhydroxyethylimidazolines include 1-hydroxyethyl-2-heptadecenylimidazoline, 1-hydroxyethyl-2-heptadecyl imidazoline,1-hydroxyethyl-2-pentadecyl imidazoline,1-hydroxyethyl-2-tridecylimidazoline and the like. Preferredpolyisocyanates include mixed 2,6- and 2,4-tolylene diisocyanates,tris(4-isocyanatophenyl)methane, 4,4'-diisocyanatodiphenylmethane,hexamethylenediisocyanate, 4,4'-diisocyanatodicyclohexylmethane,phenyldiisocyanate, and the like. The reaction mixture of step (b) ismaintained at a temperature of 95° to 100° C. for 2 to 5 hours.

The oligourethane resulting from step (b) is then quaternized in step(c). Quaternization is desirable since it introduces a polar or ioniccluster to one end of the non-polar chain of the oligourethane. Thepolar (i.e. ionic) end attaches to the pigment particle while thenon-polar end serves to sterically repel other similarly-coatedparticles, thus preventing aggregation (or flocculation) while at thesame time permitting high loadings of pigment in the dispersion.Generally the quaternizing reagent mentioned above will be utilized in amolar ratio of 0.95 to 1.0 mole per mole of tertiary nitrogen in theoligourethane. Suitable quaternizing agents include C₁ -C₄ linear orbranched alkyl sulfates, phosphates, phosphites, halides or nitrates,phosphoric acid, nitric acid, hydrochloric acid, hydrobromic acid,hydroiodic acid, p-toluenesulfonic acid and sulfuric acid esters (whichare particularly preferred).

The two-step process resulting in an oligourethane containing theurethane radical is as follows:

(a) reacting a C₃ -C₁₈ linear or branched alkyl, aryl, alkaryl, aralkyl,cycloalkyl mononofunctional alcohol or a monofunctional alcoholcontaining the radical ##STR10## with a C₁₁ -C₁₇ hydroxyethylimidazolineand a C₆ -C₁₄ polyisocyanate; and

(b) quaternizing the oligourethane resulting from step (a) by reactingit with a C₁ -C₄ linear or branched alkyl halide, alkyl nitrate, alkylphosphate, alkyl phosphite, alkyl sulfate, aryl sulfonate, alkylsulfonate or a mineral acid or halogen acid.

Suitable examples of alcohols to be employed in step (a) includehydroabietyl alcohol, butoxytriglycol and isostearyl alcohol. Thehydroxyethylimidazolines and polyisocyanates are the same as thoseindicated above for step (b) in the 3-step process described above. Themolar ratios of alcohol to hydroxyethylimidazoline and polyisocyanateare the same as in the case of the molar ratios of the ester tohydroxyethylimidazoline and the polyisocyanate; the molar ratio range ofquaternizing agent to moles of tertiary nitrogen in the oligourethane isthe same irrespective of whether the oligourethane is prepared by the3-step process or the 2-step process.

This invention is illustrated but not limited by the following Examplesin which the parts and percentages are by weight:

EXAMPLE 1 STEP A

Into a 4-neck reaction flask were charged 75.5 g 12-hydroxystearic acid,24.4 g tall oil rosin and 0.1 g dibutyl tin oxide. A nitrogen blanketwas maintained over the reaction mixture which was heated to 200° C.with agitation. The water of reaction was removed using a Dean and Starktrap and the heating with agitation was continued at 200°-205° C. forabout 10 hours until an ester having an acid value of about 70 mg KOH/gwas obtained.

STEP B

To 42.5 of the ester obtained from step A were added 19.2 g1-hydroxyethyl-2-heptadecenyl imidazoline, 0.08 g stannous octoate and30 g of heptane solvent. The reactants were warmed to reflux temperaturewith agitation while continuing the nitrogen blanket. When a solutionresulted, it was heated to 95°-100° C. and 5.5 g. tolylene diisocyanategradually added, while maintaining the temperature at about 100° C. Thereaction was complete after about 3 hours as indicated by the absence ofthe isocyanate peak at 4.45 microns under infrared spectrophotometry.The amine value of the resulting oligourethane was then measured todetermine the required amount of quaternization agent.

STEP C

The oligourethane obtained in step B was quaternized with 2.8 g ofdiethyl sulfate. The quaternization reaction was carried out, withagitation and a nitrogen blanket, at a temperature of 95°-100° C. withthe diethyl sulfate added over about a two hour period. An amine valueof 1.0 mg KOH/g indicated completion of the reaction. The product wasdischarged upon cooling to about 45° C. and was strained through a nylonbag-type filter. The product had a viscosity of about 50 poises at 25°C. by Gardner tube, a varnish standard color of 12, a solids content of70% N.V. in heptane and a specific gravity of 0.89.

EXAMPLE 2

Example 1 was repeated with a modification in that polyethylene glycol200 was also added to the reactants in step B. The reaction mixture forstep B was as follows:

    ______________________________________                                        Example I - step A ester                                                                              28.2 g                                                oleyl imidazoline       25.5 g                                                polyethylene glycol 200 2.1 g                                                 stannous octoate        0.1 g                                                 heptane solvent         30.0 g                                                ______________________________________                                    

The reactants listed above were heated and agitated in the same manneras in Example 1 and 7.7 g tolyl diisocyanate were gradually added, whilemaintaining the temperature at about 100° C. In step C, quaternizationrequired 6.4 g of diethyl sulfate indicating a higher degree ofquaternization in the final product.

EXAMPLE 3

15.3 parts of the quaternized oligourethane solution from Step (c) ofExample 1 were dispersed in an Eiger mill with 27.7 parts heptane, 7.0parts n-butyl alcohol and 50.0 parts of cyan blue pigment. Thedispersion particle size was too fine to be measured on a grind gaugeand was of the order of 0.2-0.3 micrometers. 18.5 parts of thisdispersion were mixed for 5 minutes in an Ultra Turrax Mill with 9.8parts of polyvinylchloride copolymer resin and 7.5 parts polyesterplasticizer, 1.0 part wax, 48.2 parts n-propylacetate and 15.0 partsisopropylacetate. The resultant ink, after being printed on a polyesterfilm, showed a much stronger color development than a comparable ink atthe same pigment level but which did not contain the quaternizedoligourethane of the present solution.

EXAMPLE 4

In this example, an alcohol was employed as the starting material forthe 2-step process in order to obtain a quaternized oligourethane thatcontained the urethane radical rather than the amide radical. 15.48parts of hydroabietyl alcohol and 6.1 parts butoxytriglycol were mixedwith 25.8 parts of 1-hydroxyethyl-2-heptadecenylimidazoline, 0.1 partstannous octoate and 29.9 parts reagent grade n-heptane in a 4-neckround bottom flask equipped with mechanical agitator, thermometer, dryN₂ inlet, reflux condenser and addition funnel. The mixture was heatedunder N₂ to 95°-100° C. for solution. Toluene diisocyanate, 12.208parts, was then added dropwise at a rate so as to maintain reflux atabout 100° C. After 3-4 hours reaction at 95°-100° C. no IR NCOabsorption peak was observed at 4.45 micrometers.

10.409 parts 98% diethyl sulfate was then added dropwise over one hourat 95°-100° C. After 1-2 hours at 95°-100° C. an amine titration of 1.0mg KOH/g indicated that quaternization was essentially complete. Thesolution was cooled to 40°-50° C. and strained through a nylon organdybag filter. The solution had the following properties:

    ______________________________________                                        Viscosity:      200-300 poises @ 25° C.                                Color:          11 Gardner                                                    Solids:         70 + 1%                                                       ______________________________________                                    

The quaternized oligourethane solution prepared as above (13.2 parts)was dispersed with 37.8 parts heptane, 6.0 parts n-butyl alcohol and43.0 parts 2B red pigment in an Eiger Mill to give a dispersion withpigment particle size between 0.2-0.3 micrometers. The dispersion wastoo fine to measure on a grind gauge.

The resultant red 2B dispersion (20.3 parts) was blended for 5 minuteswith 28.8 parts maleic resin, 9.0 parts ethylacetate, 23.4 partsethanol, 13.5 parts of a 35% solution of nitrocellulose and 5.0 partswax in the Ultra Turrax Mill. The resultant ink after printing onuncoated bleached paper stock showed better color development at thesame pigmentation level as an ink which did not contain the quaternizedoligourethane.

EXAMPLE 5

The quaternized oligourethane solution prepared in accordance withExample 4 (10.5 parts) was dispersed in an Eiger Mill with 50.4 partsheptane, 4.8 parts n-butyl alcohol and 34.3 parts diarylide yellowpigment. The dispersion was too fine to be measured on a grind gauge andwas in the range of 0.2-0.3 micrometer particle size.

The diarylide yellow pigment dispersion (24.5 parts) was mixed with 8.1parts n-propyl alcohol, 23.0 parts isopropyl alcohol, 24.4 partspolyamide resin, 5.0 parts naphtha, 8.0 parts maleic resin, 4.0 partswax and 3.0 parts water in an Ultra Turrax Mill in the same manner asabove. The resultant ink, when printed on high slip polyethylene andpolypropylene films, showed better heat resistance, better gloss andbetter color strength versus the same ink made at the same pigmentationlevel without the quaternized oligourethane of the present invention.

EXAMPLE 6

The same apparatus as described in Example 4 was employed in thisexample. 28.59 parts 1-hydroxyethyl-2-heptadecenylimidazoline, 16.87parts butoxytriglycol, 0.1 part stannous octoate and 29.90 parts heptanewere mixed. The mixture was heated to 95° C. under a nitrogen blanketand thereafter dropwise addition of 12.81 parts toluene diisocyanate wasbegun. The rate was adjusted to maintain the temperature below 100° C.,and the urethanation reaction was completed in about 3 hours as noted bythe absence of the NCO peak at 4.5 microns as determined on ananalytical infrared spectrophotometer.

Thereafter, 11.73 parts 98% diethyl sulfate were added over one hour at95°-100° C. After 1-2 hours at 95°-100° C., an amine value titration ofless than 1.0 mg KOH/g indicated that quaternization was complete. Theproduct was cooled to 45°-50° C. and filtered through a nylon bagfilter. It had the following properties.

    ______________________________________                                        Viscosity:      130-200 poises at 25° C.                               Color:          12 Gardner                                                    Solids:         70 + 1%                                                       ______________________________________                                    

EXAMPLE 7

This example employed the same apparatus and general procedure asdescribed in the preceding examples. A quaternized oligourethanesolution was prepared from 27.04 parts 1-hydroxyethyl-2-heptadecenylimidazoline, 6.4 parts butoxytriglycol, 13.69 parts isostearyl alcohol,0.1 parts stannous octoate, 29.9 parts heptane, 12.12 parts toluenediisocyanate and 10.75 parts 98% diethyl sulfate. After the product wascooled to 45°-50° C. and cast through a nylon bag filter, it had thefollowing properties:

    ______________________________________                                        Viscosity:      120-200 poises at 25° C.                               Color:          11 Gardner                                                    Solids:         70 + 1%                                                       ______________________________________                                    

EXAMPLE 8

The procedure of Example 7 was repeated in order to obtain a quaternizedoligourethane solution based on 21.75 parts1-hydroxyethyl-2-heptadecenyl imidazoline, 27.53 parts isostearylalcohol, 0.1 part stannous octoate, 29.9 parts n-heptane, 12.18 partstoluene diisocyanate and 8.54 parts 98% diethyl sulfate. The productafter cooling exhibited the following properties:

    ______________________________________                                        Viscosity:      30-50 poises at 25° C.                                 Color:          9 Gardner                                                     Solids:         70 + 1%                                                       ______________________________________                                    

EXAMPLE 9

This example was carried out in order to provide material forcomparative purposes and its use is shown in the table below. Using thesame type of equipment as described in Example 4, 75.5 parts12-hydroxystearic acid, 24.4 parts tall oil rosin and 0.1 partdibutyltin oxide were mixed. The mixture was heated to 200° C. and heldat that point for 9-12 hours until an acid value of 69-71 mg KOH/g wasobtained. To 93.5 parts of this reaction product maintained at 70° C.were added 6.5 parts polyethyleneimine. The temperature of the mixturewas slowly raised to 150° C. at which point a slight exothermic reactionoccurred. The reaction mixture was held an additional 4-6 hours at thistemperature until an acid value of 50-55 mg KOH/g was obtained.Thereafter, the molten oligomer was cooled to 120° C. and heptane wasslowly added under reflux to provide a 70% nonvolatile content solution.The solution was then cooled to 40°-50° C. cast through a nylon organdybag filter and such solution exhibited the following properties:

    ______________________________________                                        Viscosity:        5-10 poises at 25° C.                                Color:            14-15 Gardner                                               Solids:           70 + 1%                                                     Acid Value:       52.0 (on solids)                                            ______________________________________                                    

EXAMPLE 10

In this example, various quaternized oligourethane solutions wereutilized to provide the dispersions indicated in the table below. Thequaternized oligourethane solutions were utilized as 70% solids solutionin heptane.

                  TABLE I                                                         ______________________________________                                        Quaternized                                                                   Oligourethane                                                                 Source         Ex. 1  Ex. 1  Ex. 9                                                                              Ex. 6                                                                              Ex. 7                                                                              Ex. 8                             ______________________________________                                        Quaternized                                                                   Oligourethane                                                                 Amount         16.3   13.4   12.6 15.3 15.3 15.3                              Red Lake C     --     44.0   41.3 --   --   --                                Carbon Black   50.0   --     --   --   --   --                                Bon Pigment    --     --     --   50.0 --   --                                Bon Red Pigment                                                                              --     --     --   --   --   50.0                              Cyan Blue      --     --     --   --   50.0 --                                Heptane        26.7   36.6   40.3 27.7 27.7 27.7                              n-Butyl Alcohol                                                                               7.0    6.0    5.8  7.0  7.0  7.0                              ______________________________________                                    

As is evident from the table indicated above, the quaternizedoligourethane solution of Example 1 allowed a higher Red Lake C pigmentloading versus comparative Example 9, while still maintaining acceptableviscosity. The table above further indicates the benefit of obtainingfree-flowing dispersions at relatively high loadings of pigments,thereby presenting the ink manufacturer and user with wide formulationlatitude.

We claim:
 1. A quaternized oligourethane having the formula: ##STR11##wherein X represents the radical ##STR12## such that when X is ##STR13##R' is an ester resulting from the reaction of a C₂ -C₁₈ hydroxyalkanoicacid or a C₃ -C₁₈ hydroxyalkenoic acid and rosin, and when X is##STR14## R' is a C₃ -C₁₈ linear or branched alkyl, phenyl, alkaryl,aralkyl, cycloalkyl or the radical ##STR15## wherein Y is hydrogen ormethyl, R'" is a C₁ -C₆ alkyl and m is an integer of 1 to 20;R is a C₁₁-C₁₇ linear or branched alkyl, alkenyl, alkynyl or cycloalkyl; R" is aC₆ -C₁₄ linear or branched alkyl, phenyl, alkaryl, aralkyl or cycloalkylor a dimer or trimer thereof; R"" is hydrogen or a C₁ -C₄ linear orbranched alkyl; and Z is R""OSO₃, Cl, Br, I, NO₃ R'""SO₃,(R"")_(3-n)H_(n) PO₄ or (R"")_(3-n) H_(n) PO₃ wherein n is an integer of 0 to 3,and R'"" is phenyl, CF₃, C₁ -C₄ linear or branched alkyl or C₇ -C₁₂aralkyl or alkaryl.
 2. The quaternized oligourethane of claim 1 whereinthe rosin is tall oil rosin.
 3. The quaternized oligourethane of claim 1wherein X is the radical ##STR16##
 4. The quaternized oligourethane ofclaim 1 wherein the ester is that which results from the reaction of aC₆ -C₁₈ hydroxyalkanoic acid with tall oil rosin.
 5. The quaternizedoligourethane of claim 1 wherein R' is the radical ##STR17## wherein Yis hydrogen or methyl, R'" is a C₂ -C₄ alkyl and m is an integer of 2 to10.
 6. The quaternized oligourethane of claim 1 wherein R is a C₁₁ -C₁₇linear alkenyl.
 7. The quaternized oligourethane of claim 1 wherein R'is a C₇ -C₁₃ aralkyl or alkaryl.
 8. The quaternized oligourethane ofclaim 1 wherein Z is C₂ H₅ OSO₃.